Planning off-grid solar: a practical guide for your property

Before choosing panels or batteries, work out what life on your property will ask of the system. A weekend cabin, a full-time home and a farm workshop need different conversations, even when they share a postcode.

This guide helps you prepare for an off-grid design discussion around Kyogle and the Northern Rivers. Use it to organise your requirements and compare the assumptions behind proposals. For information about working with AzTech Renewables, visit our off-grid solar systems page.

1. Describe an ordinary day—and a demanding one

Start with a simple appliance list. Include refrigeration, lighting, internet equipment, cooking, hot water, heating and cooling, water pumps and workshop tools. Beside each item, record its model, when you use it and roughly how long it runs. Mark anything you cannot comfortably switch off or postpone.

Then describe two days: an ordinary day and a busy day when several people or pieces of equipment need power. Tell your designer which appliances are likely to run together, and flag pumps and machinery so their starting requirements can be checked.

For an occupied property, gather electricity bills and available meter or monitoring records across different seasons. A new build needs an estimated appliance schedule instead. Include future changes such as electric vehicle charging, electric hot water or an additional dwelling. Government guidance recommends considering both present and future electricity use when sizing solar. Australian Government: Size your solar system

2. Ask what happens in the difficult months

A sunny-day demonstration does not explain how the system will behave through a run of poor weather. Ask the designer which seasonal generation and demand assumptions underpin the proposal. Off-grid systems need to account for periods of low solar generation. Your Home: Batteries

Describe changes in how you use the property: winter heating, summer cooling, visitors, irrigation or seasonal work. Ask for the proposal to explain what stays available during a low-generation period, what you may need to defer, and when backup generation would be used.

These questions turn “Will it run my house?” into something a designer can assess against your actual priorities.

3. Look at the site as well as the roof

Trees, nearby buildings and other obstructions can shade panels. That shading changes with the time of day and season, and future tree growth can matter too. A site assessment should consider these factors alongside the available panel area. Australian Government: Design considerations

Before the visit, collect ground-level photographs of the roof or proposed array area. Note nearby trees, planned buildings and where you expect equipment to be located. For a new property, bring the site and building plans. Ask which locations need inspection before the layout can be confirmed.

4. Define what you mean by battery autonomy

Battery autonomy is the period you want stored energy to cover your chosen loads without replenishment. Discuss it as a design target, with a stated load and starting charge level, rather than a blanket promise of a certain number of days.

Battery capacity is measured in kilowatt-hours (kWh). Ask about usable capacity, not just the nominal figure: the manufacturer’s permitted discharge range affects how much stored energy is available. Your Home: Batteries

Ask your designer to compare the cost and operating implications of more storage, changing when you use flexible loads, and accepting some generator operation. Also ask how the battery would recharge after a low-solar period. A larger battery alone is not a complete design.

5. Give the generator a clear role

A generator can form part of an off-grid system’s plan for prolonged poor weather. Depending on the equipment and controls, starting may be manual or automatic. Your Home: Batteries

Ask what would trigger it, what it would supply, and who would operate and maintain it. Discuss fuel availability, servicing, noise and suitable placement with the installer. If you already own a generator, provide its model and specifications rather than assuming it will integrate with a proposed system.

6. Plan expansion before buying equipment

Write down changes you are considering, even if they are several years away. Separate firm plans from possibilities so the designer can explain what to allow for now and what can wait.

Ask which parts of the proposed system could expand, what limits apply, and whether expansion depends on particular compatible products remaining available. Manufacturers offer modular systems, but expansion and compatibility are specific to the equipment and design. Victron Energy: Off-grid

7. Bring a short project brief to your installer

Your first conversation will be more useful with these details ready:

• Location, property use, occupancy and whether grid power is available.
• Appliance list, operating times and equipment that may run together.
• Essential loads and tasks you could defer during poor weather.
• Bills, interval data or existing system monitoring, where available.
• Existing panel, inverter, battery and generator model details.
• Site photographs, building plans and known shading concerns.
• Future loads, preferred timeframe, budget range and attitude to generator use.

You do not need to calculate the final system size yourself. Off-grid design requires specific expertise. Ask the installer to explain the design assumptions, equipment compatibility, operating limits, handover information and ongoing service arrangements before you commit. Australian Government: Design considerations

Turn your notes into a property-specific discussion

AzTech Renewables is based in Ettrick and serves Kyogle and the wider Northern Rivers, including Lismore. Bring your project brief and the questions you still need answered.

Discuss your solar or off-grid project or call 0402 628 618.